We hear so much about child concussions in sports like hockey and football, but we hardly ever hear about a much more common source of brain injuries in kids.

Falls, on the playground or in the home, are the number one cause of brain injuries in children, while car accidents rank second. In fact, children ages 0 to 4 years are much more likely to sustain a concussion than either school-age kids or preteens.

“It’s important to be aware that with children, concussive-type injuries can occur in almost any setting,” says Ryan Coates, MD, a pediatric neurologist at Loyola University Health System in Maywood, Ill. Here’s a quick concussion primer, covering all the facts concerned parents need to know.